Interested to Buy Any Domain ? << Click Here >> for more details...
Define candidate key, alternate key, composite key?
- 30 Answers
- 145688 Views
- IAS, IBM, I also Faced
- E-Mail Answers
Answer Posted / shreyas joshi
Candidate key- A candidate key is defined as an attribute or
set(combination) of attributes that no 2 tuples(rows) in a
relation hold duplicate values of it.or we can say that a
candidate key is a kind of superkey, if whose subset taken
than it cannot be said as a superkey..in otherwords consider
a customer table with attributes(cust_id,cust_name,cust_street).
than candidate key is (cust_name,cust_street)(combination)
Now this is sufficient to uniquely identify an entity in a
table.But if its subset taken i.e alone cust_name or
cust_street, they individually cannot identify uniquely a
tuple or entity..IN short a candidate key is a superkey with
no super key as it subsets.
| Is This Answer Correct ? | 11 Yes | 3 No |
Post New Answer View All Answers
In which database can extended stored procedures be added?
The count() function always returns a int value type what should you do if you need to count rows from a query which you know will return a value that is too large for an int value type?
Explain about the database management systems.
Explain about relational operator join?
Does QTP Support the Propjects which are running in Dot Net? As we are starting with new project in Dot net need to use automation tool?Please advice & let me know what would be the best.
I have a few records all are same structures data, I want to store data in multiple targets how
Which data type cannot be used as a parameter in a udf?
How can you fix a poorly performing query?
How to generate OIDS
You have a table with three columns: amount1, amount2, and amount3 in a single row only one of these three columns will have a value and the other two will be null. Write a sql query to retrieve the values from these columns?
You have two tables with a one to many join based on a field named id. You need to find records in the parent table that are not represented in the child table. how would you accomplish this?
What is an application role and explain a scenario when you would use one?
Explain about post-relational databases?
What is database design and development?
Where is dbms used?
